No power/No display

Check the fuse.
Check impedance of rectifier bridge: 2.1M; supply power of 80V by isolation transformer, voltage of rectifier bridge +、 − :around 120V: impedance of Q3~Q8(IGBT): 10K
Check impedance of T2’s output voltage: impedance of D20: around 5.7K; Voltage: around 7V; impedance of C3/C57: around 309Ω; Voltage: around 5.2V; impedance of C5:0.6K; voltage:around 3.3V; impedance of C38:1.6M; Voltage: 15V
Check U37 on main board: ( check impedance between leg 1, leg 2, leg 3 ,leg 5 and leg 8[ground], whether it is in short circuit.